Machine for inspecting workpieces



Jung 12, 1951 F. R. BOOSEY ETAL 2,556,413

MACHINE FOR INSPECTING WORKPIECES Filed March 5, 1946 5 Sheets-Sheet l June 12,1951 F. R. BOOSEY ETAL 2, ,4

MACHINE FOR INSPECTING WORKPIECES Filed March 5, 1946 5 Sheets-Sheet 2 24 2 52/ mama 22 mm SUBMITTED.

PARTS ACCEPTED. l7

fm/enfars' HQ ICI-FEDERICA IPOBEAT 80085),

dZ/mr [all/HM, Azaewr bmmp Casi-457a mm 004,915: Joy/Y ///m r June 12, 1951 F. R. BoosEY EIAL 2,556.413

MACHINE FOR INSPECTING WORKPIECES Filed March 5, 1946 5 Sheets-Sheet 3 Patented june 12, i951" UNITED STATES PATENT OFFICE Edward Castleton,

and Charles John Hart,

Letchworth, England, assignors to The Sigma Instrument Company England Limited, Letchworth,

Application March 5, 1946, Serial No. 652,090 In Great Britain March 15, 1945 4 Claims. 1

This invention relates to machines for inspecting work-pieces. In the production of work-pieces to some standard pattern it becomes necessary to ensure that the work-pieces are correct to. a nominal standard of correctness. Usually in the'mass production of work-pieces the dimensions of these work-pieces are fixed with certain limits of error .tolerance. It is an object of the invention to -devise a machine which will be capable of inspecting work-pieces and permitting them to be sorted according to whether they are nominally correct or oversize or undersize as regards any particular dimension that is of importance. According to the invention a machine for inspecting Work-pieces comprises a bed, measuring devices disposed upon the bed to measure several dimensions of the work-piece, a workpiece holder arranged to receive a work-piece and to displace it to a gauging position where it is gauged or inspected by all said measuring devices, and further arranged to withdraw the inspected work-pieces from said gauging position there being electrical circuits controlled by said measuring devices so that according to whether ameasuring device records undersize or oversize or-n'ominal correctness of the piece in regard to the dimension inspected thereby, such electrical circuits are set to operate correspondingly recording and/or indicating means. Following the principles of the invention a machine may be de signed which is wholly automatic as regards the feeding of the Work-pieces and, moreover the recording means may take the form of sorting means automatically controlled according to the results of the gauging inspection. This will become apparent from the description which follows hereinafter.

For a better understanding of the nature Of the invention a constructional form thereof will now be indicated ingreater detail by way of example, and with reference to the accompanying drawings in which- Figure 1 is a side elevation of a machine indicating the layout of the parts thereof,

Figure 2 is a corresponding front view of the machine,

Figure 3 is a section through the principal op erating mechanism of the machine,

Figures 4 and 5 together form a, wiring diagram showing the electrical circuit arrangements, and

Figure 6 shows diagrammatically an electrical device indicated in outline only in Figures 4 and-5.

. ameters.

It will be seen from Figs. 1 and 2 that the machine essentially comprises a horizontal bed I the front end of which is built up to contain feeding mechanism whilst the rear end carries a pair of vertical pillars 2. A transverse member 3 is secured to the pillars 2, and has brackets 4 for the supporting mechanism 5 of two measuring devices 5 secured to it. In this example there is a third measuring device 1 whose fixing bracket 8 is rigidly attached to a further transverse member 9 secured indirectly to the bed I of the machine. For the sake of simplicity in this example, it is supposed that the particular work-piece which is to be inspected by the machine has three dimensions of importance. A representation of the work-piece W is engraved upon a panel Ill which is secured at the upper ends of the pillars 2. It will be observed that the work-piece W consists of a small collar which is shouldered at either end to have three principal external di- Each of the measuring devices 6 and 1 are constructed in a, precisely similar manner. As will be appreciated from the description which follows hereinafter, the precise nature of the measuring devices is not of importance for the purpose of the present invention. It will suifice to indicate that each such device possesses a reference anvil l i and a primar gauging anvil l2. Apair of opposed electrical contacts are arranged in the body of each device and their setting is controllable with the aid of the contact control heads I3 and M. The body of each measuring device essentially contains a pivoted lever one end of which carries an electrical contact that may engage the contact corresponding to the head I3 or the contact corresponding to the head it. The angular position of the lever is determined by translational gauging movements performed by the primary gauging anvil l2. The supporting mechanism of each of the measuring devices permits these devices to be adjustably secured in any desired position with regard to their supporting brackets, and the reference gauging anvils I I may also be adjustably secured in a desired position. It will be readily appreciated that if a workpiece is placed between a reference gauging anvil II and a primary gauging anvil l2 of, say, one of the measuring devices 6, the measuring devices may be so adjusted that if the external dimension which is being callipered by that device is nominally correct, the lever within the body of the device engages neither of the electrical contacts therein. If the component which is being callipered should have a dimension greater than permitted by the upper limit of tolerance,

counting device 3 therefore probably wholly rejectable.

of nominally correct dimensions.

limit Of tolerance, then the anvil P2 will tend to move slightly downwardly and hence the lever within the measuring device can be set over to an opposite position where it engages the other contact. The measuring devices 6 serve to gauge the diameters of the right and left hand ends of the work-piece W as seen in the representation of the work-piece upon the panel IE3. An engraved leading line i connects one of the dimensions concerned with a pair of signal windows It and IT. and the window H a minus indication. Above the window l5 there may be seen the indicating mechanism ll? of a counting device of known kind. Associated with the window I! there is a similar indicating mechanism counting device. In a like manner, the central dimension of the work-piece is joined by an engraved leading line which associates this dimension with a set of signal lights 2| and 22 each having associated counting devices 23 and 24.

The third dimension of the work-piece W is indicated by the engraved leading line 25 having the associated windows 26 and 21 and counting devices 28 and 29. On the right-hand end of the panel there is a further window 3!) bearing the 1 letters 0. K. and associated therewith is a At the left-hand end of the panel there is a counting device 32 in association with which are engraved the words Total parts submitted. In association with the window 30 and counting device 3| there is the engraved legend Total parts accepted.

The casing 32 built up at the front of the bed I, as previously indicated, serves to contain feeding mechanism for the work-pieces to be inspected. There are two lateral outlets 33 and 34 through which the work-pieces that have been inspected may leave the machine. As seen in Fig. 2, there is a main outlet 35 also intended for escape of tested ,or inspected pieces. In a manner which will be understood from the description which follows, the outlet 33 is concerned with pieces which are oversize i. e., work-pieces that may be corrected, whilst the outlet 34 is associated with pieces which are undersize and The outlet 35 may then be concerned with the discharge of pieces which are nominally correct, that is to say within the limit of tolerance of error set for the work-piece.

It will now be useful to indicate how the machine, briefly described above, is intended to operate. Work-pieces are fed from a hopper H into .a reciprocating work holder which .carries the work-pieces one by one to a gauging position between the various gauging anvils of the measuring devices .6 and 1. These latter gauge the Work and if all the dimensions of a work-piece are gauged as being nominally correct, only the signal window 30 is illuminated and the counters 3| and 32 operate to show that another workpiece has been submitted and accepted as being As soon as the work-piece has been so gauged it is released into a chute and is directed to the outlet 35. Each The window It bears a plus indication l9 of a known time a work-piece reaches the gauging position between the gauging anvils, the work-piece is caused to press against a light pointer indicated in chain-dotted lines at 36 in Fig. 1 which serves to close a switch 31. The closing of the switch 31 causes the counting device 32 to operate and indicate that a further part has been submitted for examination.

If the work-piece or part is gauged as being undersize in regard to one of the dimensions, for example the dimension indicated by the leading line |5 upon the panel, then the signal Window I1 is illuminated and the counting mechanism l9 makes a record. Simultaneously shutter mechanism operates to cause the part or work-piece to emerge through the outlet opening 34 when the work-piece is removed from the gauging position.

The machine may be so set up that if any one of the three dimensions measured is found undersize, the submitted work-piece is rejected through the outlet opening 34. If on the other hand no dimension is found undersize but one or more dimensions are detected as being oversize, then the part may be rejected through the outlet opening 33. It will be appreciated that in gen-- eral if a work-piece is rejected as undersize, that work-piece may have to be scrapped, whereas if it is oversize it may be altered subsequently so as to make it acceptable. In this connection it will be noted that if internal dimensions of a work-,

piece are being checked, where these dimensions are greater than permitted by an allowable limit of tolerance, this will correspond to an undersize work-piece although the particular dimension concerned is in point of fact oversize. Thus in referring to a work-piece herein as being undersize, this expression is taken to mean that the work-piece has too little material in it as judged by some standard of nominal correctness. A similar meaning in an opposite sense is to be ascribed to the word oversize used hereafter.

Reference will now be made to Figs. .4, 5 and 6 of the drawings, which show diagrammatically the electrical circuit employed for one constructiona'l form .of the invention. The three measuring devices .6 and 1 are diagrammatically illustrated and since they are all identical as regards construction, the details of one of them will sufiice to indicate the nature of the rest. One of the devices 6 has a pivotally mounted arm 38 the pivotal anchorage being indicated at 39. The free end of the arm 38 may co-operate with either of the contacts 40 or 4|. When the arm 38 cooperates with neither of the contacts 40 and 4|, the gauging anvil associated with measuring device 6 is then recording nominal correctness in the work-piece that is being gauged. If the arm 38 engages the contact 40 this corresponds to, say, undersize of the gauged dimension, whereas if the arm co-operates with the contact 4| this would then correspond to oversize. A lead 42A connects the contact 40 with a terminal 43A upon a terminal strip 44A. A second lead 45A connects the contact 4| with a further terminal 45A upon the terminal strip 44A (see Fig. 5). From the terminal 43A 2. lead 42 exends to a terminal 43 upon a terminal strip 44 (see Fig. 4). Similar-ly, a lead 45 extends from the terminal 43A to a terminal 46 upon a terminal strip 41. The terminal strip 44 is associated with a relay device RI the details of which are shown in Fig. 6, and the terminal strip 41 is associated with an exactly similar relay device.

The terminal 43 (Fig. 6) connects with a conducting spring blade 48 with which there is associated a blade 49 carrying a contact 50. When the relay associated with the terminal strip 44 is not being energised, the contact 50 engages the spring blade 43, and the blade 49 is connected to one side of a coil 5I. The other side of the coil is joined to a lead 52 which is connected with a terminal 53 upon the strip 44. Connections 54 and 55A (Fig. 4) join the terminal 53 over a switch Z to a lead 55 running to the terminal 56 of one side of the secondary winding 51 of a transformer. The other side of the winding 51 has a terminal 58 joined by a lead 59 to a terminal 69 of a junction box 6| (Fig. 5) from whence a lead 62 runs to a conducting bar 63 carrying a spring blade 64 insulated from it. A contact 65 on the spring blade is adapted to cooperate with a contact screw 66 supported in a pivoted. lever 61. The pivot may be considered as lying at the point 68 which is indicated as being earth connected. It will be observed that the pivot point 39 of the arm 38 is joined by a lead 69 which is similarly shown as earth connected as at 10. The lever 61 has a follower roller 'II engaging the periphery of a cam disc 12. A portion of the cam disc 72 is seen in Fig. 5 and an arrow indicates the direction of rotary motion of the disc. The periphery of the disc bears two cam surfaces I3 and 14 so that the lever 61 has three positions of angular adjustment about its pivot 63. There is the position illustrated where the follower 'H is riding upon the cam surface I4 which represents an intermediate position. There is next the upper-most position of the follower H Where it rides upon the periphery of the cam disc I2, and finally the lowest position of the cam follower H where it rides upon the cam surface (3. The disc I2 is driven at a uniform speed by a motor I5 which serves also to drive the workpiece feeding arrangements. When a work-piece is in position between the measuring devices and is being gauged, the follower II is nearing the end of its travel upon the cam surface 13. The contact screw 66 and contact 65 are, as shown, in engagement when the follower II is upon the intermediate cam surface 14. Such engagement 4 continues until the follower III rises upon the periphery of the cam surface when it is broken and it is resumed only when the follower 'H falls to the level of the lowest cam surface 13.

The primary winding 57A of the transformer having the secondary 5'! is joined by leads I5 and 11 to a pair of terminals 16A, HA upon the junction box 6|, from whence leads I8 and I9 complete a circuit to mains terminals 99 and BI (see Figs. 4 and 5). In the lead I8 there is included a fuse 82 and a switch 83. The third mains terminal 84 is connected to earth, A coloured lamp 85 is connected by a lead 86, and by a lead 81 which is joined to the connection I9. Thus the pilot lamp 85 serves to indicate whether the switch 83 is in the on or off position and thus whether the electric supply is available to the machine.

It will now be understood that the terminals 56 and 59 of the secondary winding 57 serve as the supply terminals for the internal circuits of the machine. Assuming for the sake of explanation that the work-piece has just arrived between the measuring devices, and is being gauged, then the lever 61 will have its follower II upon the lowest cam face I3 and the contact screw 66 will be co-operating with the contact 65. The blade 64 is however insulated from the conducting member 63, and carries an additional contact 88 adapted to co-operate with a contact 89 carried a lead 92 extending to a terminal 93 upon the terminal strip 44. Thus when the gauging of the work-piece is taking place the terminal 58 of the secondary winding 51 is not effectively in electrical connection with the contact 65, for the reason that the contact pair 88 and 69 are not in co-operation and thus the arm 38 which is earthed, has no electrical supply from the lever 61. The arm 38 may therefore, engage either of the contacts 40 or M without any danger of sparking since there is no electric circuit closed by such engagement as long as the contacts 89 and 89 are not in co-operation.

Let it be supposed that the dimensions gauged by one of the gauging devices 6 correspond to undersize of the work-piece, then the arm v38 will engage the contact 49 and will remain in this position as long as the work-piece is being gauged. The disc I2 continues to rotate until the follower II rises up upon the cam face 14. In this posi tion the lever 67 swings the contact screw 66 downwardly and permits the contacts 88 and 89 to engage. Under these circumstances a circuit is completed from the terminal 58 of the winding 51 through lead 59, lead 62, conducting member 63, contact 89, contact 88, contact 65, contact screw 66 and hence to earth. The circuit is continued from earth to the arm 33 which is then engaging the contact 49 which is connected to the terminal 43 of the relay device R. The circuit is continued through the contact 59 (Fig. 6) the winding 5!, lead 52, terminal 53, lead 54 and lead which is connected to the other terminal 56 of the transformer secondary.

Completion of the circuit described above will result in the energisation of the winding 5! of the relay B. This winding is arranged upon a core 94 with which is associated an armature 95 carried upon a lever 96 pivotally mounted as at 91. The armature 95 is attracted to the core 94 and causes a finger 99 upon the lever 96 to engage a contact blade 99 and to force the latter upwardly so that its contact I99 is brought into engagement with a contact IfilI carried by a blade I02. A distance piece I53 of insulating material is supported by the blade I92 and is also partially supported by the blade 49. A further blade I64 is also associated with the insulated distance piece I03. The lever 96 serves to operate a counting mechanism I03 of known type, which mechanism advances one step when the armature 95 is attracted to the core 94. Return movement of the armature 95 to its normalposition illustrated in Fig. 6, is not recorded by the counting mechanism I05.

The finger 98 can move the blade 99 upwardly in two stages. In the first stage the upward movement is suflicient only to produce engagement of the contacts. I99 and ItI. In the second stage the insulated distance piece I 03 is moved bodily upwardly with the result that the contact 59 no longer engages the blade 48. Before however the contact 59 is so disengaged, an electrical circuit is completed as between the terminals 53 and 93 as follows. From the terminal 53 the connection 52 is joined to one end 563' of a further winding I08 upon the core 94. The other end of the winding I69 is joined to a lead E99 connected to the blade 99. The circuit is continued by the ed to the reject opening 01' the machine.

7 contacts I and NH and is thus extended to the terminal 93. From this latter terminal a connection Q2 extends to the terminal 9i of the junction box EI. Hence the coil )8 is now energised and this coil is of heavier duty type than the coil :EI. There will be a momentary period when both coils I98 and iii are simultaneously operating, but as the heavy duty coil Hi8 causes the armature 95 to be strongly attracted to the core 9%, the insulated distance piece its will move to disengage the contact 56 from the blade =38 and thus the coil SI will no longer have its circuit completed. The two stage operation of the lever 96 will now be understood since the first stage corresponds to operation of the starting coil 5I, which operation serves merely to connect the main coil I88 for the second stage operation during which the counting device I05 is operated and the distance piece 503 is moved to break the circuit of the coil in by opening of the contact 56. The circuit completed through the coil I68 will no longer include the measuring device 5, which will in fact be totally de-energised by the disengagement of the contact 58. The signal lamp H0 is connected in shunt across the coil E08 and therefore when the latter is energised the lamp III] will light. This lamp corresponds to the minus signal window indicated at 2'! in Fig. 2.

The movement oi the insulated distance piece I03 serves also to displace a contact II I into engagement with a contact i I2 carried upon a blade i iii. The latter is connected with a terminal I M upon the terminal strip H. A lead i IE3 joins one side of a Switch He the other side or which is connected to a lead ill joined to a terminal IIB in the junction box ii i. From the terminal I 58 a lead H9 passes to one side of a winding lZil the other Side of which is connected by a lead 25 to the conducting member E53.

It will now be appreciated that when the contact pair I H ant i 52 are closed, a circuit is completed from the terminal 58 of the winding 5'! through the terminal Bil of the junction box (SI and by the lead 62 to the conducting member 83 from whence lead iZl connects to one side of the winding I213. The other side of the winding 29 is joined by lead H8 to the terminal I28 and from thence to the switch H6 via the lead i l5 to the terminal I 15. From this terminal the circuit is completed via the closed contact II2 and III thence to terminal 53 and via leads 5d and SE to the other terminal 5%; of the winding 5?. The energisation of the coil 52?, following the closing of the circuit indicated, causes an armature to be moved (not shown) whereby a deflecting shutter is set for deflection of the work-piece that is being gauged. T126 winding :25 is energised for the reason that the gauging operation has revealed that a dimension is such as to correspond to undersise of the worlopiece and this winding is associated with the shutter which causes the work-piece to be subsequently deflect- In addition to controlling an armature in the manner indicated, the winding 525 is arranged to control a blade i2? having a contact 23. The latter normally engages a contact but is pulled away from engagement therewith when the winding is en rgised. .Lhere is a further winding corresponding to the winding 52% and inten l for operation oi a deflecting shutter oversize wor -pieces. This winding l2: has likewise assoc ed with it a blade ififi having contact i2! associated with a contact I28 with which it normally cooperates. When the winding 525 is energised, the blade I26 is deiiected away from a normal position where it causes the contacts I21 and E28 to be in engagement. It will be seen that both the blades I26 and 222 are connected together and the contact S28 i connected via a lead I29 to a blade I30 having a contact lfli. There is an insulated extension i32 secured to the blade I38 and arranged to co-operate with a set-screw I33 adjustably fixed in the extremity of the lever 61. A blade I3 1 is connected with the conducting member 63 and carries a contact E35 intended to co-operate with the contact 53%. In the position of the mechanism illustrated, it will be observed that the contacts i3! and i355 are held out of engage ment by the set-screw i33 which i pressing upon the insulated finger 232 of the blade I30. It will iowever be clear that the contacts I35 and I3I will also be held out of engagement when the follower H is on the lowest cam surface I3. It is only when the follower II rides upon the :periphery of the disc 12 that the lever 61 swings to a position where it permits the contacts I3I and I35 to engage.

Up to the present, in the description hereinbefore, the operation oi the machine has been described when the iollower H occupie a position upon the lowest cam surface I3 and upon the intermediate cam surface ":4. When now the disc T12 continues to rotate the follower 'II will next ride upon the periphery of the cam which may thus be regarded as the uppermost cam surface. Under these conditions the lever 61 will swing so as to cause the contact screw 66 to be disengaged irom the contact '65. The contacts 88 and 89 will however remain closed. The opening of the contacts and will have no effect except to open the circuit which had previously existed between the measuring device 6 and the coil 51 of the associated relay device. This same circuit had of course, previously been opened when the contact 59 disengaged from the blade t8. However, it is desirable to break this same circuit for a second time for the reason that when the relay device including the coils iii and 108 is no longer energised, it will not necessarily be desirable that the contact 58 should close onto the blade 48 and thereby produce immediate re-energisation of the coil iii of the relay device.

In addition to the breaking of the contacts 65 and 65 the movement of the follower 'lI onto the periphery of the disc 1'2 causes the set-screw I33 to ride down to an extent sufficient to allow the contacts i35 and l3I to engage. In the particular example under consideration, it has been assumed that a component has been gauged by the gauging device 6 having the contacts 40 and M and has been found undersize with the result that the arm 38 engaged the contact 40. The winding i 28 associated with the deflecting shutter for defleeting an undersize component was therefore operated As will be appreciated, where the winding I253 is operated this indicates that the component under examination is not acceptable. Accordingly the counting mechanism 3| which is to indicate total parts accepted must not be operated in respect of this particular work-piece which is being inspected. This is assured by the opening of the contacts I23 and I24 due to energisation of the winding I20. Assuming for the moment that the winding l2!) had not been energised and similarly the winding I25 had also remained de-energised, then under these circumstances both the contact pairs I23, I24 and I21, i255 would have remained closed. Since the contacts I35 and I3I are closed in the position of the mechanism now being described, a circuit might then have been completed between terminals I36 and I31 of a terminal strip I38. This will be appreciated when it is observed that the terminal 56 of the winding 51 is joined by a lead I39 which connects with the terminal I36. The terminal I31 has a connection I40 to a terminal MI in the junction box 6|. From this point a lead I42 connects to the contact I24 and if this contact is in engagement with the contact I23, the circuit is continued through the contact pair I21, I28 through the lead I29 to the blade I30. Assuming that the contact pair I 3|, I35 are in engagement, the circuit is continued through the blade I34 to the conducting member 63 from whence by means of lead 62, terminal 60 and connection 59, a junction is made with the terminal 58 of the winding 51. The other terminal 56 of this same winding is already connected to the terminal I36 and therefore a circuit is closed as between the terminals I36 and I31. The contact strip I38 is intended to receive a relay device of precisely the character generally indicated at R. in Fig. 4 and shown in detail diagrammatically in Fig. 6, and therefore if a circuit is completed as between the contacts I36 and I31 the starting winding corresponding to the winding 5| of the relay device R is energised. As will be recalled, this has the effect of energising the main winding I68 and of effectively disconnecting the terminal I31 (corresponding to the terminal 43) from the relay device. The terminal I43 is however, brought into the circuit of the main relay winding. It will be observed that this terminal is connected by a link to the lead I40 which is joined with the terminal MI. The main winding will thus be connected to the circuit previously used to energise the starting winding. When the main winding of the relay is energised, the counting mechanism thereof indicated at 3I in Figs. 2 and 4 records the fact. It will be understood that the counting mechanism will not operate until the main winding of the relay is excited and this can only occur where the circuit of the starter winding as between the terminals I36 and I31 is first closed. This latter condition is fulfilled only if the contacts I23, I24 and also I21, I28 are closed and if moreover the contact pair I3I, I35 is closed. Once the starting winding has been energised, the circuit is transferred to the main winding as between the terminals I36 and I 43 and these will continue to have a circuit completed between them as long as the contacts I3I and I35 remain closed. The 0.. K. lamp 30 is illuminated when the main winding of the relay is energised.

In the example of operation which is being considered for the purposes of description, the winding I20 has operated and accordingly the contact pair I23 and I24 have been separated. Under these conditions the relay associated with the terminal strip I38 will not be energised and the closing of the contacts I3I and I35 will have no effect. The follower 1I thereforecontinues to ride around upon the periphery of the disc with only the contacts 88 and 89 effectively 00- operating. So long as these contacts remain closed, the main winding I08 of the relay R. will continue to be excited and will hold the contacts I I I and I I2 into engagement, with the result that the winding I20 will continue to be excited. This allows sufiicient time for the work-piece that is being gauged to be withdrawn from the gauging position and to be directed into a chute in which is included a deflecting shutter under the control of the winding I20. As the disc 12 continues to rotate, the follower will leave the periphery of the disc and will fall to its lowest extent upon the cam surface 13 once more. By this time the work-piece which has been gauged will have fallen through the outlet chute and will have been deflected according to the results of gauging. The next work-piece will be in the gauging position and the follower 1I will cause the lever 61 to swing to a position where the contacts 88 and 89 are disengaged, and the contacts 65 and 66 brought into co-operation. Simultaneously the contacts I and I8I will be disengaged. Thus the main winding I08 of the relay R-will no longer be energised since its circuit will be broken when the contacts 88 and 89 are separated, and therefore the winding I20 will no longer be energised since the contacts II2, III will separate. The contact I23 will therefore be released to engage the contact I24 once more The cycle may now recommence for the next work-piece.

It is to be observed that during the time when actual gauging is taking place and when for example the arm 38 was engaging the contact 40 for the first time, no circuit was closed by the co-operation of the arm 38 with the contact 40. Thus no undesirable sparking occurred during the delicate gauging operation. It was only after the gaugin had taken place that the follower 1I rose up onto the intermediate cam surface 14 and caused the contacts 88 and 89 to co-operate, thereby exciting the starting winding 5| of the relay. When the main winding I03 operated as a result, this served to disconnect the measuring device 6 from the circuit so that if thereafter the work-piece had been immediately removed, then whether it had been gauged as undersize as in the example, or as oversize or nominally correct, if the arm 30 should nevertheless co-operate with the contact 40 when the work-piece be removed (removal of the workpiece may have the effect of causing an indication that an undersize work-piece is present when in fact no work-piece is in position), this will not have any undersirable effect, since the measuring device 6 will be isolated until a next work-piece is in position and is being gauged.

A terminal strip I49 is associated with the second measuring device 6 and is concerned with the undersize indications thereof. This measuring device 6 has a contact I50 which is joined over the terminal strip MA by lead I5I to the terminal I52 of the terminal strip I49. The terminal I58 of the strip I49 has a lead I54 extending to one side of a switch I55 which at its other side is connected to the lead II1.- The other terminals of the terminal strip I49 are connected in parallel with corresponding terminals upon the strip 44. A relay R. is connected upon the terminal strip I49. This relay will be understood to operate in precisely the same manner as the relay R, associated with the strip 44.

A terminal strip I56 is associated with the undersize gauging movements of the measuring device I. The contact I51 of the device 1 has a lead I58 connected to a terminal I59 upon the terminal strip I56. The terminal I60 is in a like manner connected by a lead I6! to a switch I62 the other side of which is also connected to the lead I I1. The remaining terminals of the terminal strip I56 are connected in parallel with the corresponding terminals of the strips 44 and I49. Again, a relay R precisely similar to that ii associated with the terminal strip 4 co-operates with the terminal strip 55.

There is a further terminal strip 53 of precisely the same kind as the terminal strips previously described and intended to cooperate with an exactly similar relay device R. In this case however the indicating lamp associated with the relay device is omitted since it is desired only that the counting mechanism should be operated by the relay so as to indicate Total parts submitted. The counting mechanism of this relay device is identifiable with the counting mechanism shown at 32 in Fig. 2. The terminals i6 and :65 which are associated with the starting winding of the relay are respectively connected by leads E66 and iii? to the terminal 56 of the transformer secondary winding 5'5 and toone side of a switch W8. The switch 563 corresponds to the switch 3? shown in 1 and is closed when a work-piece is in position for gauging. lhe other side of the switch is joined by a lead His to the other terminal 58 of the winding 5'5. Thus when a part is submitted and causes the contacts of the switch let to close, a circuit is completed winding of the associated relay. The terminal I'll) of the strip E63 is connected with the lead 82 so that when the main winding of the relay is brought into circuit as between the terminals I64 and are the circuit through these terminals is completed via lead as, terminal 9!, lead contacts 38 and 89, conducting member 53, lead 62, terminal 62, lead Eil and hence terminal 58 of the winding 5?. The main excitation winding of the relay therefore continues to operate until the contacts 58 and 89 are broken. It will be observed that the contact strip E63, has the terminal X joined by a lead Y to one side of the switch Z. Thus if the main winding of this relay operates, the terminals X and are effectively bridged and the switch Z is by-passed.

From the description so far given of the operation of the switch Z it may appear completely superfluous. It is included for the following reason. If. the machine should be operated without actively submitting work-pieces for gauging, the relays concerned with undersize indications may record that undersize work-pieces are being submitted when in fact no work-pieces are being presented for gauging. Ehis error of recording could be detected by checking against the Total parts submitted since the relay associated therewith. will not operate under these circumstances as the switch 558 will not be closed. To avoid this inconvenience the switch Z is included and it is closed when the switch N58 is closed. It likewise remains open if the switch :53 is open. Hence if the machine runs empty (1. e. without work-piece feeding) the switch Z breaks the return circuit of all the other relays to the terminal 56 of the winding 5?. If a machine is operated without a Total parts submitted relay, then the switch Z remains closed or is omitted, as desired.

The contact strip G? previously referred to, is likewise furnished with a relay device R. The terminal strip fill is concerned with the oversize gauging indications of the first described measuring device 5. The terminal and the terminal I'll are concerned with the starting winding of the relay. The terminal E?! is joined to a lead I12 connected to the lead L39 which extends to one side of the transformer winding 5?. The other terminal as already seen hereinbefore, is associated with the contact 4! or" the measuring through the starting tion box 6!.

device 6; The terminal N3 of strip 41 is joined by a lead IM to one side of the switch H5 which connects to a lead H5 joined with a terminal I'll in the junction box El. From the terminal I11 there is a connection I18 to the electro-magnetic winding I25. This winding is arranged to control the oversize shutter in the work-piece outlet chute.

The terminal I19 of the strip 41 is joined by a lead I86 which connects with the lead M4. It will now be understood that if the arm.38 of the measuring device 5. engages the contact 41, a circuit may be completed to the starting winding terminals Ill and 46 in the following. manner,

erminal of the winding 51 via lead I39, I12

to the terminal Hi, the starting winding of the relay; the terminal &6, the lead 15, the contact 's-l arm 43 to earth as at "ill, from thence to earthed lever 61' contact screw 65, contact E5, contact 88, contact 89, conducting member 63, lead 62, terminal to, lead 59 and hence to terminal 58 of the winding 52". As soon as the main winding of the relay comes into operation a par allel circuit isolating the measuring device 6 is completed as between terminals H9 and Hi over the contacts 83' and 89 (this circuit being maintained after the contacts 65 and 65 have separated).

The contact strip 58! has the same relation to the contact strip 4? as did the contact strip I49 have to the contact strip i l. The contact strip 18! is intended again to receive a precisely similar relay device R and the starting winding terminal :32 is joined by a lead I83 to the contact 184' of the measuring device 8. The terminal !85' has a lead 186 connected to one side of a switch 581 the other side of which is joined to the lead N61 The other terminals of the strip 181 are joined in parallel with the corresponding terminals of the strip 47.

Finally the terminal strip E38 is associated with the oversize indications of the measuring device I. Thestarting winding terminal H89 has a lead I96, joined to the contact IQ! of the measuring device 1'. The terminal 92 is joined by a lead I93 to one'side'of a switch l9' i connected to the common lead lit. The other terminals of the strip [88 are joined in parallel with the corresponding terminals of the strips ll, 38! and i38 (it being noted in the case of this last mentioned terminal strip Hi8 that the upper terminal is unused) From the wiring diagram of Figs. 4, 5 and 6, it will be clear that the apparatus is conveniently divided into two main parts through the junc- The latter may in fact take the form of a plug and socket and all the devices upon the mains side of the junction box 6i are housed in the casing 32 in which there are also included the work-piece feeding arrangements. The other apparatus upon the other side of the junction box 6! is preferably mounted behind the panel ll]. A single multi-strand lead may then be employed for supply of the electrical circuit behind the panel 58.

Fig. 3 shows a section through the casing 32 and serves to indicate the mechanical feeding arrangements and also the drive to the disc 12 the cam surfaces of which operate the lever 6'! and control the various contacts associated therewith which contacts may be collectively identified as the master switch. The casing 32 houses the electric motor l5 having an output shaft 2% driving, through a compound gear train 20!, a toothed annulus 282. The latter is secured to a collar 263' which internally has ball bearings 294 and 2115 serving to support it from a short shaft 206. The shaft 206 is immovably secured to the housing by a machine screw 26'! and distance piece 208. Three cam discs 209, 210 and 12 are Secured upon the sleeve 203 with the aid of spacing washers 2. The disc 12 peripherally bears the cam faces shown at 13 and it in Fig. 5 and has the co-operating follower 212 corresponding to the follower roller H of Fig. 5. The lever 61 associated with the roller is carried in a bracket 2 I3 and the switching arrangements of the master switch are not shown for the reason that they are diagrammatically illustrated in detail in Fig. 5.

The work-piece holder consists of two slide blocks 2M and 2I5 which are slidably carried through the intermediary of lateral rollers (not shown). The right hand end (as seen in Fig. 3) of the slide block 2 I4 is formed with a central slot 2l6. Work-piece supporting ridges 2l8 are formed on both the upper and lower slide blocks 2! and 2l5 so that a work-piece W may be supported between them. The actual formation of the work-piece holder for the gripping of the work-piece W will of course vary according to the nature and size of the work-piece. Both the upper and lower slide blocks 214 and 2 l 5 will have to be gapped in such manner that the gauging and reference anvils may reach without hindrance, those surfaces of .the work-piece which have to be callipered. The design of the work holder must also be such that when the slide blocks 2! and H5 move relative to one another (to cause the ridges 2H3 to move relatively away from one another) the work-piece W may drop into the outlet chute 2 l ii.

The upper slide block 285 has a slot 229 in which a tension spring 22l is mounted, one end of such spring being hooked upon a peg 222 integral with the upper block M5. The other end of the spring is hooked to a peg 223 which is secured in the lower slide block 2M. The spring 22| therefore tends to pull the slide blocks away from their work Supporting position. Both the slide blocks are supported by side members carried upon a plate 224*, and this plate is gapped as at 225 to permit a sleeve 228 fixed to the lower slide block 2M to project therethrough. The lower end of the sleeve 226 carries a freely rotatable roller 22'. which engages the periphery of the cam disc 2H3. It will be understood that the spring 22l holds the follower 227 firmly upon the periphery of the cam disc Elli. In a similar manner the plate 226 is gapped as at 228 and allows a sleeve 229 to depend therethrough, such sleeve being fixed to the upper slide block 2L5. The lower slide block 254 is gapped at 23!} to permit the sleeve 229 to pas freely therethroughv A roller 23! is mounted for rotation upon the sleeve 229 and engages upon the periphery of the cam disc 209. Again, it will be appreciated that the spring 22! serves to hold the roller 23! into engagement with the periphery of the cam disc 2953.

Depending upon the nature of the work-pieces which the machine has to examine, the feed arrangements for ejecting the work-pieces into the work-piece holder, will vary considerably. Merely for the sake of illustration, in Fig. 3 a very simple form of supply for the work-piece W is illustrated. This hopper essentially consists of a passage member 232 arranged to bring the workpieces W to an aperture in a stationary plate 233. In the illustration of Fig. 3 the work-piece holder having the two slide blocks is shown in its extreme limit of movement towards the left and corresponds to the position of the work-piece holder for reception of a new work-piece. An escapement mechanism serves to feed one work piece at a time to the work-piece holder when it is in this work receiving position. This feed may be achieved in various ways and a slidable member 234 is shown which has an aperture 235 capable of receiving one work-piece when the aperture is in register with the aperture of the plate 233. The member 234 is moved periodically from the position illustrated to a discharge position where the aperture 235 lies over the work holder ridges M8. The member 234 may be driven from reciprocating mechanism operating with power derived from the motor I5 so that the movement of this member 234 is synchronised with the drive to the work-piece holder itself, and hence the member 234 can move up to a work discharge position at the moment when the work-piece holder is ready to receive the next work-piece.

The cam discs 209 and 2m are designed in such manner that the following operation is obtained; after a component or work-piece W has been received by the work holder and supported upon the ridges 2l8, the slide blocks 2M and 2|5 are both carried to the right by the sleeves 226 and 229 secured to them. The slide blocks move completely in unison and hence carry the workpiece immediately to the gauging position. In the gauging position there is a pause and then both slide blocks begin to return to the left. When the ridges 2E8 are both located above the open end of the chute2l9. the slide block 7H5 accelerates relative to the slide block 254, so that the ridges 2H3 separate and the component is dropped into the chute 219. Thereafter the slide block 2% accelerates so as to regain the workpiece receiving position by the time the two blocks have returned to the position illustrated in Fig. 3. It will be appreciated that when the workpiece holder is pausing with the work-piece in the gauging position, the cam surfaces 13 and 14 are being encountered by their co-operating follower ll The chute 2E9 communicates directly with the outlet aperture 35 and when a work-piece is dropped into the mouth of the chute it will normally emerge through this outlet 35. There are however two shutters 240 and 24! associated with this chute. These shutters are controlled respectively by wheels 242 and 2% which have pins 2% and 245 engaging in arms 246, 247. .A true central section through the chute 2I9 would not reveal the shutter 24f since it lies laterally upon that side of the chute 2!!! which would not appear in a central section seen in the direction corresponding to the section of Fig. 3. In a like manner both the deflecting chutes associated with each of these shutters would not appear. These deflecting chutes are however, both indicated to make the arrangement clear. There is a deflecting chute 248 associated with the deflecting shutter 2M and a further deflecting chute 249 associated with the shutter 240. The outlets of these chutes are indicated at 34 and 33.

If the shutter 24! should be caused to occupy a position where it lies across the main chute 1M9 any component passing through the main chute mouth 2|!) will be laterally deflected into the chute 2&8 and will appear through the outlet aperture 34. Should the shutter 24! remain in a normal inoperative position where it merely comprises a part of the main chute side walls, and if the shutter 24%] swings over to a position where it lies across the main chute passage 2H3, then any component passing through the main chute will be deflected rough the theoutlet 33. The lever 24! associ shutter operating meche' m of sh is under the control of an electro-mag vice having the energising winding indica wd at H8. The lever 2&8 or the shutter has a Sim-- ilar control from a winding i125. These winch ings will be seen to correspond to windings similarly numbered in Fig. 5 of the drawings. The winding izd is energised when a piece is gauged as undersize, and when this winding is energised the deflecting shutter lies across the main chute 239 and assures that the component gauged undersize will emerge through the outlet 3 Assuming that no a mansion of the work-piece corresponds to \ll'ldGlUnZE, and assuming that one or more dimensions correspond to oversize, then the other shutter 2 253 will be operated by its winding and the wcrk piecc so gauged emerge through the outlet ap;rture 33.

It will be noted that the shutter corresponding to undersize operates before the shutter corresponding to oversize with reference to the direction of travel of a work-piece through the main chute. Thus even though some dimensions of the work-piece may correspond to oversize, nevertheless if there is one dimension corresponding to undersize the work-piece will be rejected through the outlet aperture 34. This condition may be important when it is realised that undersize of a work-piece in any respect could be a fatal objection to that work-piece in the sense that it could not necessarily be altered to render it acceptable. On the other hand work-pieces which are oversize can usually, if so desired, be further treated so as to render them acceptable.

The above remarks concerning rejection of pieces which are undersize will not of course al ply generally and work-pieces which are undersize in some respect may not in fact have to be rejected where for example they are to fit into other work-pieces which could be specially shaped for the reception of undersize pieces. There may be other particular conditions surrounding inspection of a particular work-piece which serve to alter the circumstances previously indicated.

In the above described example of the manner in which the invention may be carried into efiect essentially a simple three dimension machine has been described. The principles disclosed serve as a basis for construction of other machines which might for example inpect simultaneously ten or more dimensions of a work-piece. The switches H6, H5 and 555, it! and H52, 184 serve to allow the effect of oversize or undersize in each of the three inspected dimensions to be cancelled at will. These switches may be located upon the panel EU as shown in Fig. 2. Thus if the switch H6 is brought to the off position then if the associated measuring device 6 should record undersize of the work-piece the winding I28 will not be energised and the piece will not be re jected through the outlet opening 34 if the dimension concerned represents undersize of the piece. In a like manner all the other measuring devices have switches which nullify the eiiect of their recording oversize or undersize in the inspected work-piece. Various schemes of inspecting and sorting may be carried out following the principles of the invention. Thus more than one deflecting shutter for deflecting undersize pieces might be incorporated, such shutters being arranged in a series so that a most important dimension of the work-piece efiects the setting of the first shutter in the chute with reference to the direction of travel of a work-piece through the main chute. In this manner the first shutter will cause deflection of all those work-pieces which have say an undersize concerned with the most important dimension. If the work-pieces happen to be incorrect as regards another less important dimension then they could be subsequently deflected through another shutter. Other sorting arrangements will become apparent from consideration of the principles of the present invention and the desiderata surrounding the inspection of particular work-pieces for particular purposes.

The machine described above need not necessarily be fully automatic and could be semi-hand operated in the sense that work-pieces could be placed by hand in the work-piece holder and removed therefrom after gauging. From the indications of the signal lights the work-pieces, could be hand sorted and the automatic sorting mech-v anism described could then be dispensed with. In the case where the automatic sorting is employed, the signal lamp indication of the result of inspection could be dispensed with.

It may be mentioned incidentally thatv the O. K. window shown upon the panel ID will of course correspond to the signal lamp associated with the relay device operating in'conjunction with the terminal strip I38. This relay device operates only when a part is found acceptable and the lighting of the O. K. lamp will therefore mean that neither of the windings I20 and E25 have been energised and therefore none of the gauging devices has detected any deviation of the component from nominal correctness.

The counting mechanism represents a highly desirable feature of the machine since it permits tabulation of the results of inspection. It will however be clear that in certain cases some or all of the counting mechanism could be dispensed with.

W e claim:

1. A machine for inspecting and sorting workpieces comprising a plurality of gauging devices, a work-piece holder arranged to be moved from a work-piece receiving position to a gauging position and to a discharge position, two electric circuits associated with each gauging device one of which can be rendered capable by the gauging device of being energised when the latter records oversize whilst the other of which can be rendered capable by the gauging device of being energisedwhen the latter records undersize, a relay in each of said circuits, a starting winding and a main winding in each such relay, said starting winding serving to bring the main winding into operation which then renders the starting winding inoperative, electro-magnetic sorting means under control of the main windings of the relays so as to set selectively according to the results of gauging, and a master switch operating cyclically in synchronism with said work-piece holder and having three settings the first corresponding to initial mechanical gauging of the work-piece when such master switch serves to deenergise said circuits and said main windings, the second setting allowing said circuits to be energised whilst said gauging devices are recording the results of gauging and the third setting causing the gauging devices to be isolated but permitting the main windings 'to continue to operate if they have been brought into operation.

2. A machine for inspecting and sorting workpieces comprising a plurality of gauging devices, a work-piece holder arranged to be movedfrom the work-piece receiving position to a gaugin position where the work-piece is simultaneously gauged by all said gauging devices, electric circuits associated with said gauging devices and arranged to be selectively energised according to the results of gauging, a master switch operating cyclically, a first pair of electrical contacts associated with said master switch and common to an said circuits, timing means associated with said master switch to ensure that said contacts are open and the circuits therefore de-energised whilst initial mechanical gauge setting is actually taking place and also to ensure that said contacts are closed and said circuits thus energised before a work-piece is withdrawn from the gauging position, a relay in each electrical circuit, a second pair of electrical contacts in each said circuit, each said second pair of contacts being under control of the relay in the same circuit, said contacts being arranged to engage when the relay in the same circuit is inoperative but to disengage when the relay in the same circuit is energised, thus ensuring that the electric circuit to the associated gauging device is interrupted before the work-piece is withdrawn from the gauging position, driving means for the master switch and the work-piece holder to operate them in synchronism, electro-magnetically operable sorting means under control of said circuits so as to be set selectively according to the results of gauging and thereby permit automatic sorting of the workpieces.

3. A machine for inspecting and sorting workpieces comprising a plurality of gauging devices, a work-piece holder arranged to be moved from .a work-piece receiving position to a gauging position where the work-piece is simultaneously gauged by all said gauging devices, electric circuits associated with said gauging devices and arranged to be selectively energised according to the results of said gauging, a master switch operating cyclically, a first pair of electrical contacts associated with said master switch and common to all said circuits, timing means associated with said master switch to ensure that said contacts are open and the circuits therefore de-energised whilst initial mechanical gauge setting is actually taking place and to ensure also that said contacts are closed and said circuits are thus energised before a work-piece is withdrawn from the gauging position, a first relay in each circuit, a second pair of electrical contacts in each said circuit, each said second pair of contacts being under control of the relay in the same circuit and each said second pair of contacts being arranged to engage when the relay in the same circuit is inoperative, but to disengage when the relay in the same circuit is energised, thus ensuring that the electrical circuit to the associated gauging device is interrupted before a work-piece is withdrawn from the gauging position, a third pair of electrical contacts in each circuit, said third pair of contacts being arranged to close when the said second pair of contacts disengage, a second relay in circuit with all those third pairs of electrical contacts which correspond to an undersize gauged measurement of the work-piece, a third relay in circuit with all those third pairs of electrical contacts which correspond to an oversize gauged measurement of the work-piece, said second and third relays being operated whenever any one third pair of contacts associated therewith closes, sorting means controlled by said sec- 0nd and third relays so as to sort work-pieces according to the operation of the second and third relays, driving means for the master switch and the work-piece holder to operate them in synchronism.

4. A machine according to claim 3, and further comprising a first switch under control of said second relay and a second switch under control of said third relay, said switches being in series with each other and each being arranged to open when the relay associated therewith is energised, a tabulating mechanism in series with said switches, said tabulating mechanism indicating the number of Total parts accepted, and means for energising the circuit comprising the first and second switch and the tabulating mechanism when both said first and second switches remain closed after a gauging operation.

FREDERICK ROBERT BOOSEY. JOHN LOXHAM.

ALBERT EDWARD CASTLETON. CHARLES JOHN HART.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Martinec Jan. 15, 1946 

